If you cancel out of the message to disembark from a boat (in this case when traveling to Adun'ubis), it deletes the the NPC's and thus removes the ability to disembark the boat, but leaves me ON the boat.
Please take a look at this or provide an option to cancel the disembarkment.\
*edit* I sent a DM tell about this when it happened. DM Mort and Johannes are aware of this.